[BROKEN] Add Socket::recvmsg

This doesn't work on Windows as the WSARecvMsg definition is missing, see microsoft/windows-rs#2530.
rust-lang · Jun 3, 2023 · 0b9ee46 · 0b9ee46
1 parent 5ed3b0f
commit 0b9ee46
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 2 deletions.
diff --git a/src/socket.rs b/src/socket.rs
@@ -23,7 +23,7 @@ use std::time::Duration;
 use crate::sys::{self, c_int, getsockopt, setsockopt, Bool};
 use crate::{Domain, Protocol, SockAddr, TcpKeepalive, Type};
 #[cfg(not(target_os = "redox"))]
-use crate::{MaybeUninitSlice, MsgHdr, RecvFlags};
+use crate::{MaybeUninitSlice, MsgHdr, MsgHdrMut, RecvFlags};
 
 /// Owned wrapper around a system socket.
 ///
@@ -627,6 +627,17 @@ impl Socket {
         sys::peek_sender(self.as_raw())
     }
 
+    /// Receive a message from a socket using a message structure.
+    ///
+    /// The `flags` are ignored on Windows (as the `WSARecvMsg` system call
+    /// doesn't accept flags).
+    #[doc = man_links!(recvmsg(2))]
+    #[cfg(not(target_os = "redox"))]
+    #[cfg_attr(docsrs, doc(cfg(not(target_os = "redox"))))]
+    pub fn recvmsg(&self, msg: &mut MsgHdrMut<'_, '_, '_>, flags: sys::c_int) -> io::Result<usize> {
+        sys::recvmsg(self.as_raw(), msg, flags)
+    }
+
     /// Sends data on the socket to a connected peer.
     ///
     /// This is typically used on TCP sockets or datagram sockets which have

diff --git a/src/sys/unix.rs b/src/sys/unix.rs
@@ -1010,7 +1010,11 @@ pub(crate) fn recv_from_vectored(
 }
 
 #[cfg(not(target_os = "redox"))]
-fn recvmsg(fd: Socket, msg: &mut MsgHdrMut<'_, '_, '_>, flags: c_int) -> io::Result<usize> {
+pub(crate) fn recvmsg(
+    fd: Socket,
+    msg: &mut MsgHdrMut<'_, '_, '_>,
+    flags: c_int,
+) -> io::Result<usize> {
     syscall!(recvmsg(fd, &mut msg.inner, flags)).map(|n| n as usize)
 }
 

diff --git a/src/sys/windows.rs b/src/sys/windows.rs
@@ -567,6 +567,20 @@ pub(crate) fn recv_from_vectored(
     .map(|((n, recv_flags), addr)| (n, recv_flags, addr))
 }
 
+pub(crate) fn recvmsg(
+    socket: Socket,
+    msg: &mut MsgHdrMut<'_, '_, '_>,
+    _: c_int,
+) -> io::Result<usize> {
+    let mut nsent = 0;
+    syscall!(
+        WSARecvMsg(socket, &mut msg.inner, &mut nsent, ptr::null_mut(), None),
+        PartialEq::eq,
+        SOCKET_ERROR
+    )
+    .map(|_| nsent as usize)
+}
+
 pub(crate) fn send(socket: Socket, buf: &[u8], flags: c_int) -> io::Result<usize> {
     syscall!(
         send(